Caustic Soda Lye is the liquid form of Sodium Hydroxide (NaOH), typically available as a clear, colorless, and highly corrosive solution. It is widely used in industries like textiles, paper, soap and detergent manufacturing, water treatment, petroleum refining, and chemical processing. Caustic soda lye is strongly alkaline and reacts vigorously with acids and water, releasing heat. Common concentrations range from 32% to 50%, and it must be handled with proper safety measures such as gloves, goggles, and chemical-resistant containers due to its caustic nature.